Search results for "General Computer Science"
showing 10 items of 895 documents
A real options game of alliance timing decisions in biopharmaceutical research and development
2017
Abstract In this article we examine the alliance timing trade-off facing both pharmaceutical and biotech firms in a stochastic and competitive environment. Specifically, we introduce a real options game (ROG), where a pharmaceutical company can choose between two competing biotech firms by sequentially offering a licensing deal early or late in the new drug development process. We find that, when the alliance raises the drug market value significantly, the agreement is signed late in the drug development process. This suggests that the postponement effect implied by the use of real options prevails over the biotech firms’ competition effect, which would instead play in favor of an early agr…
The Hierarchical Mixed Rural Postman Problem: Polyhedral analysis and a branch-and-cut algorithm
2017
[EN] The Hierarchical Mixed Rural Postman Problem is defined on a mixed graph where arcs and edges that require a service are divided into clusters' that have to be serviced in a hierarchical order. The problem generalizes the Mixed Rural Postman Problem and thus is NP-hard. In this paper, we provide a polyhedral analysis of the problem and propose a branch-and-cut algorithm for its solution based on the introduced classes of valid inequalities. Extensive computational experiments are reported on benchmark instances. The exact approach allows to find the optimal solutions in less than 1 hour for instances with up to 999 vertices, 2678 links, and five clusters.
Modelling and forecasting mortality in Spain
2008
[EN] Experience shows that static life tables overestimate death probabilities. As a consequence of this overestimation the premiums for annuities, pensions and life insurance are not what they actually should be, with negative effects for insurance companies or policy-holders. The reason for this overestimation is that static life tables, through being computed for a specific period of time, cannot take into account the decreasing mortality trend over time. Dynamic life tables overcome this problem by incorporating the influence of the calendar when graduating mortality. Recent papers on the topic look for the development of new methods to deal with this dynamism. Most methods used in dyna…
On the Bullwhip Avoidance Phase: The Synchronised Supply Chain
2012
Abstract The aim of this paper is to analyse the operational response of a Synchronised Supply Chain (SSC). To do so, first a new mathematical model of a SSC is presented. An exhaustive Latin Square design of experiments is adopted in order to perform a boundary variation analysis of the main three parameters of the periodic review smoothing ( S , R ) order-up-to policy: i.e., lead time, demand smoothing forecasting factor, and proportional controller of the replenishment rule. The model is then evaluated under a variety of performance measures based on internal process benefits and customer benefits. The main results of the analysis are: (I) SSC responds to violent changes in demand by re…
Modelling Offices Through Discourse Analysis: A Comparison and Evaluation of SAMPO with OSSAD and ICN
1992
In a previous paper the importance of framing office communications in terms of discourse analysis was explored. 2 It also presented an approach based on speech acts and conversations to allow this framing to occur. The approach was termed SAMPO. In this paper, we continue the discussion on discourse analysis by comparing SAMPO with two prominent office modelling approaches, Information Control Nets (ICN) and OSSAD, and discuss its merits in modelling office communications.
Using store level scanner data to improve category management decisions: Developing positioning maps
2009
This paper provides evidence of the usefulness of aggregated point-of-sale scanner data to infer the positioning of competing brands, providing valuable information for category management and hence facilitating decision making. Specifically, the authors propose a methodology to study the internal market structure based on market share models with latent heterogeneity when only macro-level time series data (not individual choices) are available. The proposed approach assumes a multidimensional decomposition, latent in the preference structure that is implicit to these types of models. By empirically applying this approach, the authors (1) simultaneously identify both latent dimensions of co…
An ontology change management approach for facility management
2014
International audience; Facility management (FM) or technical property management is an approach to operate, maintain, improve and adapt buildings and infrastructures of organizations. A FM project requires the cooperation of many actors from different domains so it has to be automated in a constrained collaborative environment. This paper proposes a new approach for ontology change management applied on facility management of such projects. The industrial challenge is, firstly, to ensure consistency of a FM project knowledge from the construction phase to the technical property management phase (after delivery). Secondly, it has to provide to each actor of the project a personal up-to-date…
Errors and Complications in SQL Query Formulation
2018
SQL is taught in almost all university level database courses, yet SQL has received relatively little attention in educational research. In this study, we present a database management system independent categorization of SQL query errors that students make in an introductory database course. We base the categorization on previous literature, present a class of logical errors that has not been studied in detail, and review and complement these findings by analyzing over 33,000 SQL queries submitted by students. Our analysis verifies error findings presented in previous literature and reveals new types of errors, namely logical errors recurring in similar manners among different students. We…
A Survey on Privacy in Decentralized Online Social Networks
2018
Decentralized Online Social Networks (DOSNs) have recently captured the interest of users because of the more control given to them over their shared contents. Indeed, most of the user privacy issues related to the centralized Online Social Network (OSN) services (such as Facebook or Google+) do not apply in the case of DOSNs because of the absence of the centralized service provider. However, these new architectures have motivated researchers to investigate new privacy solutions that allow DOSN’s users to protect their contents by taking into account the decentralized nature of the DOSNs platform. In this survey, we provide a comprehensive overview of the privacy solutions adopted by…
The effect of inventory record inaccuracy in information exchange supply chains
2015
Abstract The goal of this paper is to quantify the impact of Inventory Record Inaccuracy on the dynamics of collaborative supply chains, both in terms of operational performance (i.e. order and inventory stability), and customer service level. To do so, we model an Information Exchange Supply Chain under shrinkage errors in the inventory item recording activity of their nodes, present the mathematical formulation of such supply chain model, and conduct a numerical simulation assuming different levels of errors. Results clearly show that Inventory Record Inaccuracy strongly compromises supply chain stability, particularly when moving upwards in the supply chain. Important managerial insights…